1. Field
This disclosure is generally related to computer networks. More specifically, this disclosure is related to establishing directed routing paths across network nodes of a computer network using database synchronization operations.
2. Related Art
Link-based routing protocols, such as Intermediate System to Intermediate System (IS-IS) and Open Shortest Path First (OSPF), are designed to establish symmetric links between neighboring network nodes. Each network node propagates link state information across a network by sending link-state advertisements (LSAs) to neighboring network nodes. When a network node receives an LSA, the network node can create an updated graph for the map of the network, and updates a routing table to indicate a first node along a shortest path to each network node.
In link-based routing protocols, it is important that all nodes of a computer network operate under the same network map to prevent forwarding packets in a routing loop within the network. To maintain a synchronized network map, network nodes propagate a received LSA to other neighboring nodes of the computer network, which allows other neighboring nodes to update their routing table. Hence, because two network nodes of a computer network store the same network map, they may use the same links to route packets to each other, in opposite directions.
However, some users may not wish their devices to use the same links to send and to receive packets. For example, a user's smartphone may typically download a substantially larger number of packets than it uploads, given that the downloaded packets may typically correspond to media content that can consume significant network bandwidth. On the other hand, the smartphone's uploaded packets may correspond to relatively small pieces of data, such as an email or a Short Messaging Service (SMS) message, a request for content (e.g., a hypertext transfer protocol (HTTP) request to view a website).
If the user's cellular network provider provides a quota to the amount of bandwidth accessed by the user's smartphone, the user may prefer that his smartphone to use a Wi-Fi network connection to receive packets, while allowing his smartphone to use either the Wi-Fi connection or a cellular network connection to send packets. Unfortunately, typical link-state routing protocols do not allow the user to control which links are to be used to send packets to, or to receive packets from, the user's computing device.